Tension device for automatic loom shuttles



Feb. 13, 1934. w LUNDGREN 1,947,133

TENSION DEVICE FOR AUTOMATIC LOOM SHUTTLES Filed April 29. 1932 HI "WW"NHIIIWIHMWE mum I N V EN TOR. M44 MM 5. L MVfidM/V BY 2 a z I A TTORNE Y.

Patented F eb. 13, 1934 UNITED STATES PATENT OFFICE TENSION DEVICE FOR AUTOMATIC LOOM SHUTTLES trustee Application April 29, 1932. Serial No. 608,198

4 Claims.

The present invention relates to tensionin devices for automatic loom shuttles by means of which a uniform and sufiicient tension is exerted on the weft in order that the goods may be I' woven properly. The invention has the particular utility in shuttles for use in automatic silk and artificial silk looms in which it is necessary to provide a fixed and predetermined tension on the weft, without subjecting the thread to a frictional drag which would injure the thread. The

present invention is in some respects an improvement over the applicant's prior Patent No. 1,713,- 706 issued May 21, 1929, in which the device is automatically threaded by use of the inertia of a 16- mass of material in the shuttle which operates to place the elements of the tensioning device in threading position, said device thereafter applying a predetermined tension to said thread, in

response to a resilient or elastic tensionmember.

Although this device is entirely satisfactory in operation, the construction thereof is somewhat complicated and expensive to manufacture; said device incorporates a plurality of moving parts which render the device liable to fail in opera- 26' tion.

The principal object of the invention is to combine the advantageous features of the above structure with none of the disadvantages, thereu by providing a simplified construction which is arranged for use in automatic looms, said device operating to provide a determinable tension on each successive weft filling. The device furthermore is operative to tension the material on the first throw of the shuttle after a full bobbin has been substituted for an exhausted bobbin, said shuttle being automatically threaded during this throw. The objects and advantages of the present construction will appear from the following detailed description, taken in connection with the accompanying drawing, in which:--

Fig. 1 is a plan view of a shuttle showing the invention.

Fig. 2 is a section through the shuttle substantially along the line 2-2 of Fig. 1.

- Fig. 3 is a plan view of the device of the invention removed from the shuttle.

Like reference characters refer to like parts in the difierent figures.

Referring first to Fig. 1, the body 1 of an automatic shuttle has the usual tip 2 and is provided with a recess 3 in which the bobbin 4 is mounted,

the latter being held in position in the usual manner by a spring fork and heel plate, not shown,

with the bobbin pointing toward the tip 2 and toward the tensioning device.

The tensioning device of the invention is mounted in the end of the shuttle and is arranged to be inserted in or removed from a cutout portion 5 of said shuttle. Referring particularly to Fig. 3, the thread is guided from the bobbin 4 toward the tensioning device by a guide member 6 which comprises a cylindrical portion 7, arranged to be received in a cylindrical recess in the shuttle, and an enlarged head 8, the latter being provided with a vertical groove 9 through which the thread extends as shown in Fig. 2. The upper surface 10 of the guide 6 is slightly below the top surface of the shuttle 1 when the member 6 is in position within the shuttle.

The tensioning device is supported by a member 11 which is secured in the shuttle by a screw 12, extending upwardly through said shuttle. The member 11 has a horn 13 which extends below a guide 14 formed on a projecting portion 15 of the member 11, said guide extending toward the end of the shuttle and projecting beyond a thread groove 16 in the member 11. Said groove, when the member 11 is positioned within the shuttle, is in alinement with the groove 9 in the member 6, and defines with said groove 9 a longitudinal thread guide or passage for thread from the bobbin.

The shuttle is provided with a horizontal passage 17 beneath the horn 13 through which the thread is delivered from the shuttle, and a depending guide or finger 18 on the under side of the horn provides a guide for the thread to support said thread in the passage 17. The passage 17 is in alinement with the forward end of the groove 16 and the thread passes around a corner 19 on the member 11 as it enters the passage '17.

The left hand end of the member 11 is spaced forwardly from the right hand end of the member 6 to provide a groove or vertical channel 20 extending diagonally of the shuttle and intersec ing the guide defined by the grooves 9 and 16, and a tension member 21 is pivotally mounted in this channel on a pin 22 carried by the member 11 adjacent the right hand end of the channel. Said tensioning member is normally maintained in the position shown in Fig. 2 by a resilient member or elastic 23 which extends through an opening in the member 21 and around a hub 24 on the pin 22, with the end of said elastic 23 extending through a passage 25 in the shuttle and secured to a vertically mounted screw 26, rotation of which provides for adjustment of the tension on said elastic. The shuttle is provided with a longitudinal groove 27, in the end of which the pin 26 is mounted, the elastic member 23 extending within said groove, which, as shown in Fig. 1 intersects the passage 25 through which the elastic member projects.

Referring to Fig. 2, the tension member is substantially flat, and the upper edge 28 thereof defines an approximate involute curve about the axis 22. The lower edge 29 of the tension member is straight and substantially tangential to the hub 24 which, as best shown in Fig. 1, supports said member in a position substantially parallel to and closely adjacent to the end surface of the member 6, said member 21 being thus closer to the end of the thread groove 9 than to the groove 16. The end of the tension member 21 remote from the pivot 22 has a downwardly projecting hook 30, and a felt pad 31 is mounted in the shuttle at the base of the groove 20 in position for engagement with the hook 30 of the tension member as the latter reaches the full line position shown, thus avoiding shock which would tend to break the tension member 21 when formed of glass or porcelain.

The weight of the tension member 21 is unbalanced with the center of gravity of said member spaced from and positioned above the pivotal support for said member, and forwardly thereof as the shuttle moves toward the left, Fig. 1. Thus, as the shuttle is moved toward the left by the picker stick, not shown, of a loom in which the shuttle is mounted, the acceleration imparted by said stick causes said member to swing upwardly into the dotted line position, as a result of the inertia of the tension member 21, thereby relieving the thread of any drag thereon during the start of the movement of said shuttle toward the left.

Filaments of artificial silk or other fine materials have a tendency of coiling during the unwinding from the bobbin, and such coils, unless there is provision for allowing them to pass through the tensioning device, increase in number until a definite kink or knot is formed between the end of the bobbin and said device. The upward swinging movement of the tension member 21 removes said member out of contact with the thread and any coils in the thread thus pass out of the shuttle without forming knots.

As the shuttle comes to rest as it reaches the left hand box of the automatic loom, the resil-. iency of the elastic 23 causes the tension member 21 to return to the position shown, thereby applying a tension to the filling. The angular position of the tensioning member in the shuttle is such that, as said tension member moves downwardly, it forms a relatively sharp downward bend in the filling at the forward or right hand end of the groove 9, although the angle formed by the thread between said tension device and the groove 16 is much greater. Thus, as will be apparent, the downward movement of the tension member 21 provides a material tension on the filling in the groove 16 with a much less tension on the filling in the groove 9, thereby establis i g a tension on the filling which is transmitted to the last woven weft thread to tension the same. During the return movement of the shuttle to the right, as the shuttle reaches the right hand box and the motion of said shuttle is stopped, the inertia of the tension member 21, during the slowing down or negative acceleration of the shuttle, causes said member to swing up to relieve any tension on the thread and to allow kinks to pass by said tension device. The tension me 21 then. urn to e full li e nq iien under the influence of the elastic 23 and establishes a tension on said filling at the right hand end of movement substantially equal to the tension applied at the end of the left hand movement of the shuttle. Successive weft fillings are thus woven under equal tension and the cloth will be evenly woven, without the inequalities resulting from uneven thread tensions.

In threading the tensioning mechanism, it will be assumed that a full bobbin has just been placed within the shuttle by the usual transferring mechanism of the loom, the shuttle being in the right hand box of an automatic loom. The end of the filling 32 at that time extends directly from the bobbin 4 to a filling holder or knob provided by the loom for holding the ends of the fillings of bobbins in the magazine. The filling thus extends above the grooves 9 and 16 and above the tensioning member 21, and rests in a groove 33 in the shuttle. As said shuttle is now moved to the left, the filling passes around the forward end of the horn 13 beneath the guide 14 to enter the grooves 9 and 16. In response to the acceleration of the shuttle, however, toward the left, the tension member 21 swings upwardly out of line with the grooves 9 and 16 into its dotted line position by reason of its inertia, thereby leaving said grooves free for the thread to enter therein. When the acceleration resulting from the push of the picker stick is no longer eifective, the tension member 21 returns toward the full line position under the influence of the elastic 23, with the thread 32 beneath said member, said member thus tensioning the thread or filling during the first throw of the shuttle after replacement of an exhausted bobbin. On the subsequent movement of the shuttle toward the right, the filling passes beneath the guide 18 into the opening 17 into the normal position for said filling during the operation of the shuttle, the guide 18 maintaining said filling in the opening 17 during subsequent left hand movements of the shuttle. The hook 30 overcomes any tendency of the filling to pass over the end of the member 21, and thus prevents the device from becoming unthreaded.

It will thus be noted that the present invention provides a shuttle which is automatically threaded and which applies a substantial tension to the filling at the end of the first pick of the shuttle after a full bobbin has been placed therein, the tension applied for subsequent movements of the shuttle being substantially equal to the tension applied at the end of the first pick of the shuttle.

I claim,

1. The combination with a shuttle having a longitudinal thread passage through which a thread is normally directed, said shuttle having a diagonal groove therein intersecting said passage, of a tension member in said groove, resilient means for holding said member in thread tensioning position, and means for pivotally supporting said member with the center of gravity thereof spaced from the pivotal support to procure swinging movement of said member to inoperative position upon the picking of said shuttle.

2. The combination with a shuttle having a longitudinal thread passage through which a thread is normally directed, said shuttle having! a diagonal groove therein intersecting said passage, 4

of a tension member in said groove, resilient means for holding said member in thread tensioning position, and a pivotal support for said member in'theend of said groove adjacent the end of the shuttle to procure movement of said member to inoperative position upon the movement of said shuttle.

3. The combination with a shuttle having 9. Iongitudinal thread passage through which a thread is normally directed, said shuttle having a diagonal groove therein intersecting said passage, of a tension member in said groove, and means for pivotally supporting said member with the center of gravity of said member spaced from said pivot to procure swinging movement of said member out of thread engaging position in response to acceleration of the shuttle in which the device is located, and resilient means to normally hold said thread member in thread tensioning position.

4. The combination with a shuttle having a longitudinal thread passage through which a thread is normally directed, said shuttle having a groove therein intersecting said passage and extending diagonally of said shuttle, of a substantially flat tension member in said groove, means for pivotally supporting said tension member with the center of gravity of said member spaced from said pivot to procure swinging movement of said member out of alinement with the thread passage upon acceleration of the shuttle in which the device is located, and resilient means normally holding said member in thread engaging position with the lower edge of said member beneath the'longitudinal thread passage.

WILLIAM E. LUNDGREN. 

